Capturing of Environment Polluting Metal Ions Co2+, Ni2+, Cu2+, and Zn2+ Using a 3-Azomethine Benzanthrone-Based Fluorescent Dye: Its Synthesis, Structural, and Spectroscopic Characterizations

The increased use of benzanthrone-based fluorescent dyes in industry and medicine, has stimulated our attempts to extend the scope of these dyes to capturing environmentally hazardous metal ions. For this purpose, a 3-azomethine benzanthrone-based fluorescent dye containing the hydroxy group at the o -position of benzene ring in the azomethine fragment has been synthesized and referred to as LH . Its ability to capture Co 2+ , Ni 2+ , Cu 2+ , and Zn 2+ metal ions from aqueous solutions was investigated. The binding mode, molecular structure, thermal and morphological characteristics, and spectroscopic properties of the LH complexes have been studied by magnetic moment, CHN analysis, fluorescence, 1 H NMR and IR spectroscopy; SEM, TEM and XRD analysis, and thermogravimetry. Experimental data support the two L – anions coordination to each metal ion as a bidentate ligand. Complexes of LH with Co 2+ , Ni 2+ , and Cu 2+ ions are formulated as [M L 2 (H 2 O) 2 ], and the Zn 2+ complex is expressed as [Zn L 2 ]. Thermal, XRD, and TEM analyses have indicated the complexes as thermally stable of nanoscale size particles ranging from 10 to 43 nm.